[lldb][windows] do not attach to a PseudoConsole if it is not opened (#177934)

# Summary

This patch ensures lldb will not try to read from a PseudoConsole if it
has not been opened.

# Original issue

https://github.com/llvm/llvm-project/pull/168729 introduces support for
the Windows ConPTY in `lldb-dap`. This caused a regression in `lldb`
which was not caught by our tests:
https://github.com/llvm/llvm-project/issues/175652.

This patch fixes https://github.com/llvm/llvm-project/issues/175652.

`lldb_private::ProcessLauncherWindows::LaunchProcess` connects the
debuggee to a PseudoConsole only if:
```cpp
if (hPC != INVALID_HANDLE_VALUE && launch_info.GetNumFileActions() == 0 && launch_info.GetFlags().Test(lldb::eLaunchFlagLaunchInTTY))
```

lldb needs to check the same condition in
`lldb_private::PlatformWindows::DebugProcess` to ensure that it does not
read from a PseudoConsole which has not been opened.

# Side effect

This patch reverts what https://github.com/llvm/llvm-project/pull/168729
did by adding ConPTY support.
https://github.com/llvm/llvm-project/pull/175812 is the proper fix,
however it's causing tests failures which we can't reliably reproduce at
desk. Given https://github.com/llvm/llvm-project/pull/168729 breaks
`22.x` lldb, it's better to revert the change ahead of the release of
`22.x` rather than pushing for the proper fix.